Browse the library
Batch Number vs. Lot Number
What batch and lot numbers mean, where the two terms part ways, and how either one ties a container to its analytical records.
Dipeptide vs. Tripeptide vs. Polypeptide
How peptide size names work, from two residues up to long chains, with real examples and the counting rules behind each term.
How Are Peptides Named?
A single peptide can have a systematic name, a sequence name, a trivial name, a code name and a nonproprietary name. This guide…
How Does HPLC Work?
How does HPLC work? Here is what actually happens during a run, step by step from mobile phase to finished chromatogram, and…
How Does Mass Spectrometry Work?
Follow a peptide through a mass spectrometer, one stage at a time: sample inlet, ionization, mass analysis and detection.
How Many Amino Acids Are in a Peptide?
The number of amino acids in a peptide runs anywhere from two to roughly fifty. Where those numbers come from, how to count…
How to Read a Peptide Certificate of Analysis (COA)
Seven steps to read a COA for a peptide, worked through on an annotated sample report and then on a clearly labelled illustrative…
How to Read an HPLC Chromatogram
How to read the axes, peaks and integration of a peptide HPLC chromatogram, step by step, ending with an illustrative worked…
What Is HPLC? HPLC Testing for Peptides Explained
High-performance liquid chromatography, commonly called HPLC, is an analytical separation technique used to investigate the…
HPLC vs. Mass Spectrometry
HPLC tells you how much of a sample is the main component. Mass spectrometry tells you what that component is. This is how HPLC…
Identity vs. Purity in Analytical Testing
Confirming what a sample is and measuring how much of it is the intended compound are two separate questions. Different methods…
In Vitro vs. In Vivo Research
In vitro, in vivo, ex vivo and in silico, defined. Plus where clinical phases and reviews sit, and how Vinnix labels the evidence…
What Is LC-MS?
LC-MS feeds liquid chromatography straight into a mass spectrometer, so each peak separated from a peptide sample can also be…
What Is Mass Spectrometry?
Mass spectrometry turns peptides into ions, measures their mass-to-charge ratio and tells you whether a sample is the molecule…
Molecular Weight vs. Molecular Mass
One peptide can carry three slightly different mass values. Here's why, and which one to use when you read a product record or a…
One-Letter vs. Three-Letter Amino Acid Codes
Amino acids carry two sets of abbreviations. Here's where the letters of the one-letter code came from, and when each notation is…
What Is a Peptide Bond?
How a peptide bond forms, why it's flat and rigid, and why it holds peptide chains together so dependably.
Peptide Purity Explained
Peptide purity describes the composition of a sample. A purity percentage only means something alongside its method, sample…
Understanding Peptide Sequences
How to read a peptide sequence: one-letter and three-letter codes, N- and C-termini, and the notation used for modified residues.
Peptide Synthesis Explained
How peptides are made: biological synthesis, solid-phase peptide synthesis with Fmoc or Boc chemistry, cleavage, purification…
Peptides vs. Proteins
Peptides vs. proteins: what they share, how they differ in size, structure and production, and why there is no single cut-off…
A Guide to Sourcing Research Peptides
Seven checks for sourcing research peptides by judging each listing on its information rather than its marketing: documentation…
Understanding Peptide Research: Terminology, Testing and Analysis
A practical map for understanding peptide research: the vocabulary and analytical methods you meet when reading about peptides…
What Are Amino Acids?
How amino acids are built, why they come in L and D forms, how they are classified and linked by peptide bonds, and why their…
What Are Peptides?
What are peptides, and how do amino acids and peptide bonds put them together? This plain-English guide also covers how…
What Does HPLC Purity Mean?
How an HPLC purity percentage is worked out, what it can and can't tell you, and how to read it on a peptide COA.
What Is a CAS Number?
What a CAS Registry Number is, how its check digit works, and how to use one when you read compound records and documentation.
What Is a Mass Spectrum?
How to read a mass spectrum, from the axes and the base peak to isotope patterns, charge states and adducts, worked through with…
What Is a Molecular Formula?
How to read a molecular formula, how to write one for a peptide, and what it can and can't tell you about identity.
What Is a Peptide?
A short answer that starts from the peptide definition: what a peptide is, what it is made of, and how the word differs from…
What Is a Polypeptide?
What the word polypeptide means, how such a chain differs from a peptide and a protein, and why multi-chain proteins need the…
What Is Chromatography?
The principle behind every chromatographic separation, the main types used in laboratories and where peptide analysis fits in.
What Is Lyophilization?
How freeze-drying removes water by sublimation, the three stages of the process and what "lyophilized peptide" means on a product…
What Is Molecular Weight?
What molecular weight means, how it is calculated from a molecular formula and how to read the value listed for a peptide.
What Is the C-Terminus?
The C-terminus is where every peptide sequence ends. What it is, what -OH and -NH2 mean, and why C-terminal amidation matters for…
What Is the N-Terminus?
The N-terminus is where every peptide sequence begins. What it is, why it is written first, and how N-terminal modifications are…
What Should a COA Contain?
A field-by-field COA checklist for a peptide certificate of analysis: what each entry is for, and what its absence tells you.
Introduction
The Vinnix Research Library is where we explain the science: peptide chemistry, amino acids, molecular terminology, analytical methods and individual compounds. Think of it as the reference layer under every product page. When a listing mentions a sequence, a molecular weight or an HPLC purity figure, the library tells you what that term means and how it's measured.
We write for people who want accurate background, not marketing. Each article defines its terms, pulls apart concepts that often get mixed up, and cites published sources wherever a claim depends on them.
How the Peptide Research Library Is Organized
There are four areas, running from basic chemistry to compound-specific detail.
| Area | What it covers | Start here |
|---|---|---|
| Peptide Fundamentals | Amino acids, peptide bonds, sequences, size and synthesis | What Are Peptides? |
| Testing & Analysis | HPLC, mass spectrometry, LC-MS, purity and certificates of analysis | Peptide Testing & Analysis |
| Compounds | One profile per compound with verified identifiers and research summaries | Compound Library |
| Reference | Short definitions and editorial standards | Peptide Glossary |
Peptide Fundamentals
Start here if you want the vocabulary. Peptides are built from amino acids connected through peptide bonds. Peptide Fundamentals covers what that means and how peptides are described, and everything else in peptide research builds on it. If you're new, Understanding Peptide Research explains how studies are designed and labeled.
- What Are Peptides? The definition, structure and scope of the term.
- What Are Amino Acids? The building blocks and their side chains.
- What Is a Peptide Bond? The condensation reaction that links residues.
- Understanding Peptide Sequences: notation, termini and why order defines identity.
- Peptides vs. Proteins: where the terminology overlaps and where it differs.
- Peptide Synthesis Explained: solid-phase synthesis, purification and characterization.
Testing & Analysis
This group is about evidence on paper: how a peptide sample gets characterized, and how to read the documents that report the results. Comparing suppliers? Sourcing Research Peptides turns these ideas into a checklist, and What Is Lyophilization? covers the dry form most peptides ship in.
- Peptide Testing & Analysis: the overview guide to identity and purity testing.
- What Is HPLC? Chromatographic separation and purity reporting.
- What Is Mass Spectrometry? Mass-to-charge measurement and identity.
- HPLC vs. Mass Spectrometry: which question each method answers.
- What Is LC-MS? The combined technique and how its output is read.
- Peptide Purity Explained: what a percentage does and does not tell you.
- What Is a Certificate of Analysis? The document and its required fields.
- How to Read a COA: a field-by-field walk through a typical report layout.
Compound Reference Library
Individual compound profiles organize verified chemical information, terminology, research references and available documentation, one compound per page. Browse them in the Compound Library, or open a well-documented example such as BPC-157 to see how sequence, molecular data and cited studies sit together.
Learning Paths
A learning path is an ordered reading list in which each article builds on the last. Pick the one that fits your question.
Path 1: Peptide basics
- What Are Amino Acids?
- What Is a Peptide Bond?
- Understanding Peptide Sequences
- Peptides vs. Proteins
- Peptide Synthesis Explained
Path 2: Reading a certificate of analysis
- Peptide Testing & Analysis
- What Is HPLC?
- What Is Mass Spectrometry?
- Peptide Purity Explained
- How to Read a COA
Path 3: Researching a specific compound
- Open the compound profile in the Compound Library and note its sequence and molecular weight.
- Read the published research summary and check the study type of each reference.
- Compare the expected mass with the batch report using HPLC vs. Mass Spectrometry.
- Find the batch report in the COA Library once it is published.
How Peptide Research Is Cited
Each claim about published peptide research is tied to a PubMed-indexed reference and labeled by study type. That way you can see how strong the evidence is at a glance. We interpret research according to study design, methods, limitations and evidence type, and we keep laboratory, preclinical and human clinical findings apart.
The labels mean different things. An in vitro finding comes from cells or tissue in a lab, an animal finding from a preclinical model, and a human clinical finding from a registered trial in people. They aren't equivalent, and results from animal models often fail to carry over to humans [1]. So compound pages describe what a study investigated, rather than presenting its findings as established outcomes. The full editorial standard, including how identifiers are checked against PubChem and FDA GSRS, is in the Vinnix research methodology.
Everything here is educational. Preclinical findings don't establish safety or effectiveness in humans, and nothing in the library is guidance for human or veterinary use.
FAQFrequently asked questions
What is the Vinnix Research Library?
It's a set of educational articles on peptide chemistry, amino acids, analytical testing and individual compounds. The library explains the terms you'll see on Vinnix product pages and certificates of analysis, cites published sources where a claim depends on them, and labels each cited study by type so you can judge the evidence yourself.
Where should I start if I am new to peptide research?
Begin with Peptide Fundamentals: read What Are Amino Acids? and What Is a Peptide Bond?, then Understanding Peptide Sequences. Those three give you the vocabulary the rest of the library assumes. Once you're comfortable, the Testing & Analysis path covers how peptide samples are characterized and how to read a certificate of analysis.
How are research articles kept accurate?
Every article is checked against its cited sources, and each reference is confirmed in PubMed before it's listed. Molecular identifiers are verified against PubChem and, where it has a record, the FDA Global Substance Registration System. When a source changes or someone reports an error, the article gets revised, as the Vinnix research methodology describes.
Can I suggest a topic or report an error?
Yes, please. Email [email protected] with the page address and the topic or correction you have in mind. If you're reporting an error, include the source that supports the fix if you have one. We review every report against the original reference, and confirmed corrections are made on the page and noted in its revision record.
REFScientific references
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Pound P, Ritskes-Hoitinga M. Is it possible to overcome issues of external validity in preclinical animal research? Why most animal models are bound to fail. J Transl Med. 2018;16(1):304. PubMed 30404629
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